The Gulfstream G400 has flown with a finished interior for the first time. The fourth and final test aircraft in the program lifted off from Dallas Love Field with a fully outfitted cabin, a sign that the program has moved into late-stage validation.
The flight lasted 2 hours and 46 minutes and reached 48,000 feet. The crew used it to test cabin systems in an 11-passenger configuration with two-and-a-half living areas. Gulfstream President Mark Burns shared the details at NBAA-BACE in Las Vegas. The flight stayed below the 51,000-foot certified ceiling.
Why an Outfitted Test Jet Matters
The first three G400 test aircraft are flying laboratories, carrying instrumentation racks and ballast instead of leather seats. This fourth jet is built to answer the questions owners actually care about: how the cabin feels, how the systems behave, and whether the whole thing works on a long day aloft.
Engineers use a jet like this to check lighting, climate control, noise levels, and galley function. Cabin pressure comfort matters too, and Gulfstream bills the G400 as having the lowest cabin altitude in its class. A lower cabin altitude means the cabin feels closer to sea level, and passengers tend to arrive less fatigued after a long leg.
The Performance Case
Another G400 test aircraft recently flew from Miami to Las Vegas on sustainable aviation fuel, holding high cruise speed over the long trip. For a deeper look at how Gulfstream approaches fuel, see our piece on the G800’s flight on pure sustainable fuel.
Gulfstream’s published figures give the G400 a strong footing:
- Range: 4,200 nautical miles at Mach 0.85
- Top speed: Mach 0.90
- Maximum cruise altitude: 51,000 feet
- Engines: Pratt & Whitney PW812GA
- Flight deck: Symmetry with active control sidesticks
- Price: list price of approximately $34.5 million
That range should typically cover transatlantic routes such as New York to London, though actual performance depends on payload, winds, and reserves. It also handles most of the routes owners fly day to day.
Where It Fits in the Gulfstream Lineup
The G400 sits below the G500 and G600 in Gulfstream’s large-cabin range, above the super-midsize class. Gulfstream describes it as its first new large-cabin aircraft in over a decade, which matters because buyers stepping up from a super-midsize jet have had few fresh options. For broader family context, our guide to Gulfstream private jets covers the lineage.
Gulfstream is also building from the other direction. The smaller G300 recently completed its first flight, so the company is renewing the middle of its range at once. The G400 aims to give owners a large cabin without paying for G600 range they might never use.
The Certification Question
Gulfstream unveiled the G400 in 2021 and originally targeted 2025 deliveries. It’s now October 2026, and Burns declined to name a new certification date.
Interior and systems validation usually come near the end of a program, but Gulfstream hasn’t said how much testing remains.
For prospective buyers, this affects planning: delivery slots hinge on certification, and current aircraft may need to stay in service longer. Charter flights and jet cards can bridge the gap, and our guide to budgeting for a charter flight helps with the math.
What to Watch Next
The next milestone is the start of formal FAA certification flight testing with the outfitted aircraft. Also watch for customer reaction once buyers walk through a production-standard cabin, and for any pricing or delivery-slot response from rival large-cabin makers.